Implements RFC 9728 protected resource metadata and HEAD probe so
claude.ai can complete its pre-handshake discovery without hitting 404.
- GET /.well-known/oauth-protected-resource → 200 {"authorization_servers":[]}
- GET /.well-known/oauth-authorization-server → 404 (no auth server)
- HEAD /mcp → 200 + MCP-Protocol-Version: 2025-06-18 header
Closes#2
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Implements the Streamable HTTP transport: POST routing handles initialize
(issues session ID), tools/list, tools/call, and unknown methods; GET SSE
emits a keepalive comment then blocks on context cancellation. A minimal
registry stub is introduced so the server compiles and tools/list returns
an empty array until Phase 6+ registers real tools.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
